It is possible to record analog audio information on a magnetic tape medium or, in the form of discrete charges, on a silicon medium. Recent audio signal compression techniques allow analog audio recordings to be processed for storage in digital form on a computer hard disk, a floppy disk, or other, similar media. Recent advances in signal compression technology make it possible to store more than 1000 hours of analog recording on a single hard disk after being converted to purely digital form and compressed. Audio signal processing capability can be resident on a personal computer (PC), or other computer, in the form of signal processing software. Alternatively, audio signal processing capability can be provided to the computer by an auxiliary digital signal processing (DSP) add-on card or an external DSP peripheral. Once stored in memory on the computer as digital information, voice files can be managed by software written for that purpose.
The cost of hard disk memory continues to decrease. In addition, compression techniques continue to improve, allowing more analog audio information to be stored on less storage space. These developments make use of a computer for storing and manipulating tape-based audio information more attractive. Some disadvantages of tape-based or silicon-based storage of analog audio information are also present with current storage of digital audio information. For example, because the analog or digital audio data is present in a continuous stream, identifying and locating a particular segment requires tedious searching. In addition, editing the audio data to leave out some parts and rearrange others requires identifying and locating segments, and manual cutting and pasting.